Structural insights into the bactericidal mechanism of human peptidoglycan recognition proteins -- Cho et al. 104 (21): 8761 Data Supplement - HTML Page - index.htslp -- Proceedings of the National Academy of Sciences

Cho et al. 10.1073/pnas.0701453104.

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SI Figure 5
SI Table 3
SI Figure 6
SI Table 4

SI Figure 5

Fig. 5. Calorimetric titrations of human PGRP-IbC with PGN derivatives at 275-277 K. (A) Raw data obtained from 60 automatic injections of 1 ml of aliquot of 1.97 mM GMPP solution into 0.035 mM PGRP-IbC solution. (B) Nonlinear least-squares fit (solid line) of the incremental heat per mole of added ligand (open squares) for the titration in A. The equilibrium binding constant obtained from this titration is K_b = 2.27 ± 0.14 ´ 10⁵ M^-1, with n = 0.98 ± 0.01. (C) Raw data obtained from 135 automatic injections of 1 ml of aliquot of 0.96 mM GMPP₂ solution into 0.034 mM PGRP-IbC solution. (D) Nonlinear least-squares fit (solid line) of the incremental heat per mole of added ligand (open squares) for the titration in C; K_b = 2.35 ±0.10 ´ 10⁵ M^-1, with n = 1.07 ± 0.01. (E) Raw data obtained from 58 automatic injections of 4 ml of aliquot of 0.83 mM MPP solution into 0.047 mM PGRP-IbC solution. (F) Nonlinear least-squares fit (solid line) of the incremental heat per mole of added ligand (open squares) for the titration in E; K_b = 1.18 ±0.04 ´ 10⁵ M^-1, with n = 1.05 ± 0.01.

SI Figure 6

Fig. 6. Comparison of human PGRP-IbC-GMPP and PGRP-IaC-MPP complexes. (A) Differences at PGN-binding clefts in PGRP-IbC-GMPP and PGRP-IaC-MPP structures (1). PGRP-IbC is drawn in yellow, and PGRP-IaC in gray. Residues of PGRP-IbC contacting GMPP and corresponding residues of PGRP-IaC are shown in ball-and-stick representation. Carbon atoms are in yellow in PGRP-IbC and in gray in PGRP-IaC; nitrogen atoms are in blue, and oxygen atoms are in red. GMPP is shown in purple; for simplicity, MPP is not drawn. (B) Molecular surface of the PGRP-IbC-GMPP complex. The protein is oriented as in A. GMPP is shown in ball-and-stick representation. (C) Molecular surface of the PGRP-IaC-MPP complex. PGRP-IaC undergoes a conformational change upon binding MPP (ball-and-stick representation), whereby the ligand is locked into the binding groove by a side-chain rotation of Tyr-266 (labeled with a red asterisk). The corresponding residue of PGRP-IbC is Pro-298 (see A).

1. Guan R, Brown PH, Swaminathan CP, Roychowdhury A, Boons G-J, Mariuzza RA (2006) Protein Sci 15:1199-1206.